A toffee hammer is a very small hammer

Hammer

A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

 designed for breaking up sheets or slabs of hard toffee

Toffee

Toffee is a confection made by caramelizing sugar or molasses along with butter, and occasionally flour. The mixture is heated until its temperature reaches the hard crack stage of 300 to 310 °F...

, such as bonfire toffee

Bonfire toffee

Bonfire toffee is a hard, brittle toffee associated with Halloween and Guy Fawkes Night in the United Kingdom."Toffee is also the name given to a confection of sugar and butter boiled to hard crack, associated with both Halloween and Guy Fawkes Night." Mason,...

, into small pieces suitable for consumption. A toffee hammer is sometimes included as a novelty item in gift packs produced by toffee manufacturers.

Toffee hammers were used by suffragette

Suffragette

"Suffragette" is a term coined by the Daily Mail newspaper as a derogatory label for members of the late 19th and early 20th century movement for women's suffrage in the United Kingdom, in particular members of the Women's Social and Political Union...

s, in particular members of the Women's Social and Political Union

Women's Social and Political Union

The Women's Social and Political Union was the leading militant organisation campaigning for Women's suffrage in the United Kingdom...

, for breaking windows as a form of protest during their campaign for votes for women.

The term "toffee hammer" may also used to refer to any unusually small hammer, for example in orthopedic surgery

Orthopedic surgery

Orthopedic surgery or orthopedics is the branch of surgery concerned with conditions involving the musculoskeletal system...

,
or to a scaffolder

Scaffolding

Scaffolding is a temporary structure used to support people and material in the construction or repair of buildings and other large structures. It is usually a modular system of metal pipes or tubes, although it can be from other materials...

's tool that resembles a toffee hammer.